deposit Faulty

I bought a Blu voucher on the 25th of April for R500, but the voucher was invalid . I reported the matter to Capitec Bank for the whole 2 weeks, but I did not receive my money back. I reported the matter 3 times, they required me to call the service provider, I did call, but they said the voucher was redeemed. I don't know why Sun Bet is not refunding my money or updating my balance on the App.